TABLE 2.

Selected plasma amino acid concentrations of mice fed diets with various levels of supplemental arginine or citrulline for 2 wk¹

	Treatment diets
		Arginine-supplemented			Citrulline-supplemented
Plasma concentration, μM	Control	A1	A3	A5	C1	C3	C5	PArg	PCit	PCit-Arg2
n	9	7	7	9	9	6	7
Arginine	109 ± 11	126 ± 7	141 ± 15	159 ± 14	131 ± 11	169 ± 5	214 ± 12	0.002	<0.001	0.008
Citrulline	74 ± 2	73 ± 2	73 ± 3	71 ± 2	119 ± 4	224 ± 8	283 ± 19	0.31	<0.001	<0.001
Ornithine	94 ± 2	140 ± 7	145 ± 9	199 ± 11	123 ± 8	165 ± 8	186 ± 18	<0.001	<0.001	0.83
Phenylalanine	186 ± 4	184 ± 7	171 ± 8	183 ± 6	187 ± 6	188 ± 9	185 ± 9	0.52	0.98	0.66
Tyrosine	114 ± 6	114 ± 7	109 ± 7	111 ± 5	124 ± 9	117 ± 8	123 ± 13	0.63	0.78	0.62

¹Values are means ± SEMs. Control, 75 μmol arginine · kg⁻¹ · h⁻¹; A1, A3, and A5 provided 75, 225, and 375 μmol supplemental arginine · kg⁻¹ · h⁻¹, respectively; C1, C3, and C5 provided 75, 225, and 375 μmol supplemental citrulline · kg⁻¹ · h⁻¹, respectively.

²Comparison between citrulline and arginine; slopes differed for P < 0.05.